Uploading a file through the browser

Completely clueless about this. I have to upload a file from the machine of any guy accessing my jsp page. It has to be uploaded to the server and then i have to kick off a process that will insert the data in the file into a database. I know how to do the second part (in fact, i have done it). I am completely clueless about the first part.
Thanks a lot for your responses in advance.